2 releases
Uses new Rust 2024
new 0.1.1 | Mar 27, 2025 |
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0.1.0 | Mar 27, 2025 |
#1083 in Rust patterns
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6KB
should_error
NOTE: This crate is deprecated in favor of
should_match
.
Pass a test if an error is returned.
Setup
This crate is primarily intended for use in tests, so add it to your dev-dependencies
instead of dependencies
:
cargo add --dev should_error
Recommended to work with macro_rules_attr
:
cargo add --dev macro_rules_attr should_error
Usage
With macro_rules_attr
Simply apply
the should_error
macro (the order does not matter):
use macro_rules_attr::apply;
use should_error::should_error;
// This test will pass
#[apply(should_error)]
#[test]
fn test_apply_first() -> Result<(), &'static str> {
Err("error")
}
// This test will also pass
#[test]
#[apply(should_error)]
fn test_apply_second() -> Result<(), &'static str> {
Err("error")
}
To further specify the pattern that's expected to match, use the expected
argument:
# use macro_rules_attr::apply;
# use should_error::should_error;
#
#[test]
#[apply(should_error, expected = Err("error"))]
fn test_with_error_expected() -> Result<(), &'static str> {
Err("error")
}
You can also match anything else other than an Err
:
# use macro_rules_attr::apply;
# use should_error::should_error;
#
#[allow(dead_code, reason = "Only used in tests")]
enum MyEnum {
One,
Two,
}
#[test]
#[apply(should_error, expected = MyEnum::One)]
fn test_with_arbitrary_expected() -> MyEnum {
MyEnum::One
}
Directly
Wrap your tests with should_error!
(note that the #[test]
attribute must be wrapped inside the macro):
use should_error::should_error;
// This test will pass
should_error! {
#[test]
fn test() -> Result<(), &'static str> {
Err("error")
}
}
// This is not a valid test: the `#[test]` attribute may only be used on a non-associated function
#[test]
should_error! {
fn test() -> Result<(), &'static str> {
Ok(())
}
}
To further specify the pattern that's expected to match, use the expected
argument:
# use should_error::should_error;
#
should_error! {
#[test]
fn test_with_error_expected() -> Result<(), &'static str> {
Err("error")
}, expected = Err("error")
}
You can also match anything else other than an Err
:
# use should_error::should_error;
#
# #[allow(dead_code, reason = "Only used in tests")]
enum MyEnum {
One,
Two,
}
should_error! {
#[test]
fn test_with_arbitrary_expected() -> MyEnum {
MyEnum::One
}, expected = MyEnum::One
}